Theory of inelastic lifetimes of surface-state electrons and holes at metal surfaces

Abstract

After the early suggestion by John Pendry (1980 Phys. Rev. Lett. 45 1356) to probeunoccupied bands at surfaces through the time reversal of the photoemission process, theinverse-photoemission technique yielded the first conclusive experimental evidence for theexistence of image-potential bound states at metal surfaces and has led, over the last twodecades, to an active area of research in condensed-matter and surface physics. Here wedescribe the current status of the many-body theory of inelastic lifetimes of theseimage-potential states and also the Shockley surface states that exist near the Fermi levelin the projected bulk band gap of simple and noble metals. New calculations of theself-energy and lifetime of surface states on Au surfaces are presented as well, using theGWΓ approximation of many-body theory.